1. Field of the Invention
The present invention relates to a testing socket apparatus for measuring electric characteristics of a semiconductor device by obtaining a contact with leads extending from a package.
2. Description of the Related Art
In order to measure electric characteristics of a semiconductor device having leads extending from side walls of its package, a testing socket is used to obtain the electric connection between the semiconductor device which is an object to be tested and a testing circuit substrate.
FIG. 1 is a cross-sectional view illustrating a conventional testing socket shown in Japanese Patent Application Laid-Open No. Sho 64-23174.
Namely, in the testing socket apparatus 1, a pair of testers 4 are provided in one-to-one relation with leads 6 of a semiconductor device 7, which is an object to be tested, in a receiving space defined by a substrate 2.
In order to conduct a test of the semiconductor device 7 by using the testing socket apparatus 1, the testers 4 which extend downwardly from the testing socket apparatus 1 are inserted in advance into a circuit substrate (not shown) to fasten the testing socket apparatus thereto.
Under this condition, first of all, the semiconductor device 7 is loaded onto a loading portion 8, and a suspension 5 which holds the loading portion 8 is lowered.
Thus, a reactive force of the testers 4 is applied to the leads 6 of the semiconductor device 7 to generate a constant pressure therebetween and to obtain an electric connection between the circuit substrate (not shown) and the semiconductor device 7.
Then, a predetermined signal is fed from the circuit substrate through the pair of testers to the semiconductor device 7, and an output signal fed from the semiconductor device 7 in response to the predetermined signal is returned again through the testers 4 back to the circuit substrate to thereby conduct the electric measurement based upon the output signal.
When the measurement has been completed, the suspension 5 is raised and the semiconductor device 7 is removed from between the pair of the testers 4.
However, such a testing socket apparatus suffers from the following problems.
Namely, the semiconductor device is pressed and inserted between the pair of testers in order to ensure the contact between the leads extending from the semiconductor device and the testers of the testing socket.
For this reason, it is possible to apply the testing system to a case where the leads are J-shaped (bent toward the inside of the package) but there is a problem that the leads may be pressed in an undesirable manner so as to cause deformation of the leads in the case of other lead shapes, for example, in the case where the leads are of a gull wing configuration for "surface loading" (i.e., the tip ends of the leads are bent outwardly from the package).
In particular, the prior art device may cause undesirable deformation in a semiconductor device having a plurality of leads of fine pitch in which an interval between the adjacent leads is small, and the mechanical strength is low.
Also, since the interval between the pair of testers is kept constant, it is necessary to provide different testing sockets in conformity with the size of semiconductor device to be tested.